1. Field of the Invention
The present invention relates to a shutter device.
2. Description of the Related Art
Japanese Patent Application Laid-Open No. 2008-180815 discusses an imaging apparatus that performs an image capturing operation using not only a focal plane shutter but also an electronic shutter. The imaging apparatus starts an exposure operation using an electronic shutter function of an image sensor, and terminates the exposure operation by running a blade group constituted by a mechanical shutter.
In this shutter device, a drive lever is held by energizing an electromagnet, and thereafter, a set lever starts driving a mirror upward. After the mirror is moved upward, engagement of a blade lever is released, whereby the blade group makes an aperture open. Then, at predetermined timing, the electromagnet is de-energized, so that the drive lever and the blade lever are driven together in a direction to close the aperture.
In the shutter device discussed in Japanese Patent Application Laid-Open No. 2008-180815, the set lever rotates about an axis perpendicular to a photographic optical axis (so moves in a plane orthogonal to the light receiving face of the image sensor), whereby the mirror is retracted out of the optical path. The set lever is caused to rotate by a drive source such as a motor, whereby a charge lever rotates to charge a drive spring for driving the drive lever.
However, since the set lever rotates about an axis perpendicular to the photographic optical axis, there is an issue in that when the set lever is provided in the shutter device, the size of the shutter device increases.
Moreover, when an output shaft of the drive source such as a motor is arranged in parallel to the photographic optical axis, it is necessary to change the drive direction to drive the set lever. However, when the drive direction is changed, there is an issue in that the loss of the drive force increases.